Alzheimer's pain poorly treated, research shows
Alzheimer's Pain Treatment
In a world first study, scientists at Melbourne's Howard Florey Institute have uncovered that people with Alzheimer's disease have the same pain threshold as people without Alzheimer's disease, but have great difficulty communicating the level of pain they are experiencing.
The study has significant clinical implications and raises important concerns about the current inadequate treatment of pain for people with Alzheimer's disease.
Alzheimer's patients are administered fewer analgesics and report less clinical pain than healthy patients, so the Florey researchers investigated whether this was due to either the degeneration of central pain processing in the brain, or the inability for Alzheimer's patients to communicate the level of pain they were experiencing.
Dr Michael Farrell, PhD student Leonie Cole and their Florey colleagues collaborated with A/Prof Stephen Gibson from the National Ageing Research Institute and used functional magnetic resonance imaging (fMRI) technology for the study.
Dr Farrell said the Florey study was the first in the world to use this scientific method to examine pain processing in the brains of people with Alzheimer's disease.
"Our fMRI results revealed that people with and without Alzheimer's disease have the same areas of brain activity when experiencing moderate pain," Dr Farrell said.
"Both groups showed pain related activity in the brain's medial and lateral pain systems, and there were no signs of impairment in the brain's central pain processing areas.
"Our results confirm that in people with Alzheimer's disease, brain processing of pain does not explain a reduction in pain reported by this vulnerable group.
"The alternative explanation is that impaired thinking reduces the capacity of people with Alzheimer's disease to communicate their pain.
"Clinicians and carers must be especially vigilant when assessing pain in people with Alzheimer's disease as there is a risk of inadequate treatment," he said.
During the study, 14 Alzheimer's patients and 15 matched controls were placed in an fMRI while their thumbnails were pressed to evoke only just noticeable, weak, and moderate pain.
All Alzheimer's disease subjects had been diagnosed by a specialist memory clinic before being accepted into the study, which was approved by various human research ethics committees.
The results of this study were recently published in the prestigious international journal, Brain.